There is a wide variety of different types of agricultural machines that apply a liquid material. Some such agricultural machines include sprayers, tillage machines with side dressing bars, air seeders and planters that have row units.
As one example, a row unit is often mounted on a planter with a plurality of other row units. The planter is often towed by a tractor over soil where seed is planted in the soil, using the row units. The row units on the planter follow the ground profile by using a combination of a downforce assembly that imparts a downforce on the row unit to push disc openers into the ground and gauge wheels to set depth of penetration of the disc openers.
Row units can also be used to apply liquid material to the field (e.g., to the soil, to a plant, to a seed, etc.) over which they are traveling. In some scenarios, each row unit has a pulse-controlled valve (such as a valve controlled using a pulse width modulated signal) that is coupled between a source of liquid material, and an application assembly. As the valve is pulsed, liquid passes through the valve, from the source to the application assembly, and is applied to the field. This type of metering, using a pulsed control signal, induces a pulsing dynamic into the flow of the liquid material. Even where the valve is not controlled using a pulsed control signal, pulsation can be introduced through other sources, such as a pump.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.